Liquid trapping device



Feb. 4, 1936. A ugs 7 2,029,852

' LIQUID TRAPPING DEVICE Filed Dec. 25, 1932 INVENTOR E d guluumm I amw Y I R EYS Patented Feb. 4, 1936 UNITED [STATES LIQUID TRAPPING DEVICE Lyman A. Bliss, New York, N. Y., assignor to The Linde Air Products Company, New York, N. Y.,

a corporation of Ohio Application December 23, 1932, Serial No. 648,623 3 Claims. (01. 202-163) This invention relates to liquid protective devices and particularly to liquid protective devices for pipes or conduits arranged for the passage of vapor from one portion of a chambered apparatus to another.

The invention has for its object generally an improved construction and arrangement of parts for devices of the character indicated which is efficient, economical, and readily manufactured.

More specifically, the invention has for its object the provision of an improved device for trapping liquid and preventing its passage through a conduit leading from the vapor space of a chamber containing both liquid and vapor to a second 15 chamber where the presence of liquid is objectionable or injurious.

It is also an object to provide a desired margin of safety against the possibility of the passage of liquid in devices of the character indicated from the trap into the second chamber by con structing the device with means for increasing the resistance, particularly the hydrostatic head against which liquid must rise, to a predetermined value.

25 It is a further object to provide devices of the character indicated with traps which may be drained, the traps being constructed to be selfdraining in some instances.

Other objects of the invention will in part be 30 obvious and will in partappear hereinafter.

liquid protective device constructed in accordance 45 with the invention; and

Fig. 2 is a fragmentary view, similar to Fig. 1, but showing a modified form of the invention.

Referring now to the drawing, and particularly to Fig. 1, it denotes generally an apparatus which 50 may be a rectifying column for liquefied gases, for example, liquid oxygen, which has a chamber ii in the lowerportion of which there is a heat exchanging means it for vaporizing the liquid therein. From an exit of the vapor space of this 55 chamber there leads a conduit or passage it to an inlet of a second chamber in the apparatus, which in the column shown comprises an auxil iary heat exchanging'means or condensing chamher it, this passage having a relatively extended to vertical rtion it and a depending connection l5 that leads to the lower header of this second chamber, this second chamber also being provided with a withdrawal connection l6. Rectification columns for liquefied gases are with advantage provided with condensing chambers, such as here 5 shown at M, where it is desired to effect a high degree of purification, and as set forth in the copending application of Walter F. Moeller now Patent No. 1,967,717, dated July 24, 1934.

In accordance with the practice of the present 10 invention, the passage I3 is provided with a trap device l8 at the base of the vertical portion, arranged for catching any liquid which may enter the passage from the chamber ll, since it is desirable to prevent the passage of such liquid into the chamber M. This trap device may have any convenient form, for example a U shaped trap which has one leg communicating directly with the vapor space of the first chamber, and its other leg in communication with the vertical section I3. The trap is also preferably provided with a liquid withdrawal means comprising a connection, as indicated at l9, and has means, for example a gage glass 20, for indicating the presence of liquid in the trap device. Whenever liquid is sighted in the trap by the operator, the withdrawal connections l9 are opened to withdraw all liquid contained therein, afterwhich it is closed so that vapor can again pass freely from the first chamber to the second.

In order that the chamber I l may have the desired protection against the passage thereinto of any liquid from the vapor space of the first chamber or from. the trap device Hi, the vertical portion I3 is extended upwardly a predetermined distance in excess of that normally separating the first and second chambers, and a second trap 2i inserted in the vapor passage at the head of the vertical portion; the value of the hydrostatic head against which liquid must rise from the firstjrap device is then determined by the distance the two trap devices are separated.

I The value given is, of course, such as to impart the desired marginof safety. The vertical portion I3 thus provided rises upwardly to a point which in general is materially-above the place where the connection 15 enters the second chamber. The second trap device 2i may have any convenient form, for example, that of an inverted U, as shown in the drawing. The inverted U 2! is also preferably tapped, for example, by the provision of a passage 22, in' order that vapor may be led away when desired.

In operation, it is seen from the description abovethat the normal liquid level in the chamher H is below the entrance to the-passage is In normal operation, vapor passes freely from the chamber ii to the chamber Hi. If for any is made evident in the gage glass 20 when the operator will withdraw the same through the conduit l9. During this period of liquid accumulation .prior to the withdrawal through the con duit IS, the vapor will generally bubble through the liquid. The increasing of the hydrostatic head through which liquid must rise by the provision of the inverted U 2|, isseen to function not only to stop the passage of liquid, but also to make more likely the passage of the vapor through the liquid in the trap device I 8 in bubble form.

In Fig. 2, a modified arrangementof the device for protecting the chamber l4 against the entry of liquid is shown. Where the conduit 23 is indicated as leading from the vapor space of the chamber I I and includes not only a U portion 24 of a primary trap, but also an auxiliary trap comprising a small chamber 25 through the bottom of which the passage 23 enters and extends upwardly as a small pipe portion 23' terminating short of the upper closure of the auxiliary cham ber 25. From the top ofthe auxiliary chamber 25, the passage is continued through an inverted U portion 26 to a connection 2] that communicates with the chamber M.

The auxiliary chamber 25 is designed to receive and separate from the vapor any liquid that may come over in the passage 23. Such liquid as initially is caught in the trap 24 is ultimately discharged into the auxiliary chamber 25. This auxiliary chamber ismade self-draining by the provision of a conduit 28 which leads from the bottom of the auxiliary'chamberand communicates with the chamber H below the liquid level the auxiliary chamber. 25 to the main chamber I I at any desired rate.

Since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it is'intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a device of the character described, the combination with an apparatus including a liq- .uid heating and vaporizing chamber having a vapor space and. a second chamber located in heat exchanging relation with respect to the first chamber and adapted to receive vaportherefrom, of a passage member extending-from an exit of the vapor space of said first named chamber to an inlet of said second named chamber, said passage member including a relatively vertically extending portion, a trap device at the base of said vertical portion disposed below said vapor exit and provided with a through passage for vapor and with liquid separating and withdrawing means, and a secondtrap device at the top of said vertical portion and disposed above said inlet of said second chamber and provided with a through passage for vapor; said vertical portion of said passage member being of a length proportioned to provide a predetermined hydrostatic head and resistance against the rising of liquid therein when liquid tends to pass from the first named trap device into the second, said passage member and trap devices being arranged to provide a relatively freepath for vapor passing from the vapor space of the first named chamber to said second named chamber. v

2. In a deviceof the characterdescribed, the

combination with an apparatus including a liquid heating and vaporizing chamber having a vapor space and a second chamber located in heat exchanging relation with respect to the first chamber and adapted to receive vapor therefrom, of a passage member extending from an exit of the vapor space of said first named chamber to an inlet of said second named chamber, said passage member including a relatively vertically extending portion, a trap device at the base of said vertical portion disposed below said vapor 'exit and provided with a through passage for vapor and with liquid separating and withdrawing means, a second trap device at the top of said vertical portion and disposed above said inlet of said second chamber and provided with a through passage for vapor, and a connection for returning the liquid withdrawn from the first named trap to the liquid space of said first named chamber; said vertical portion of said passage member being of a length proportioned to provide a predetermined hydrostatic head and resistance against the rising of liquid therein when liquid tends to pass from the first named trap device into the second, said passage member and trap devices being arranged to provide a relatively free path for vapor passing from the vapor space of the first named chamber to said second named chamber.

. 3. In a device of the character described, the combination with an apparatus including a liquid heating and vaporizing chamber having a vapor space and a second chamber located in the first chamber so as to be cooled and adapted to receive vapor therefrom, of a passage member extending from an exit of the vapor space of said first named chamber to an inlet of said second named "chamber, said passage member includinga relatively vertically extending portion, a trap device at the base of said vertical portion disposed below said vapor exit and provided with a through passage for vapor-and with liquid separating and withdrawing means, a second trap device at the top of said vertical portion and disposed above said inlet of said second chamber and provided with a through passage for vapor, ,a connection for returning the liquid withdrawn from the first named trap tothe liquid space of said first named chamber, and means for visually indicating the presence of liquid in the first named trap to an attendant; said vertical portion of said passage member being of a length proportioned to provide a predetermined hydrostatic head and resistance against the rising of liquid therein when liquid tends to pass from the first named trap device into the second, said passage member and trap devices being arranged to provide a relative-v ly free path for vapor passing from the vapor space of thefirst namedchamber to said second named chamber.

LYMAN A. mass. 

